The present invention relates to a tube joint and the method of adhesively joining metal tube ends to be used in conjunction with sealed refrigerant systems. It should be noted, however, that the joint may be employed in other applications requiring fluid tight joints.
The use of adhesive, such as epoxy resin adhesives, for joining metal tubes is well known. For example U.S. Pat. No. 3,068,563--Reverman discloses a method of joining metal tubes. In accordance with the teachings of the Reverman patent, a first tube or member having a passage therein is prepared to receive a second tube with a small but definite clearance between the two contiguous surfaces. An adhesive such as an epoxy resin is applied either to the exterior of the second tube or to the interior surface of the telescoping passage after which the second tube is inserted into the passage. The first tube or member is then worked to reduce the diameter thereof substantially throughout the extent of the inner tube and at the same time groove or crimp the outer tube or member to mechanically interlock the two components. Finally, the adhesive is heated to curing temperature. It should be noted that the integrity of the joint is arrived at only when the heating and curing of the adhesive is accomplished. Accordingly, this curing procedure must be carried out before the joint is fluid tight to the extent that it may be used in a charged refrigeration system. This requires that, during the manufacturing process, provisions be made so that the joint be heated to cure the adhesive which is both time consuming and expensive.